1. Field of the Invention
The present invention relates to an endoscope system used to conduct endoscopy with an endoscope inserted in a subject.
2. Description of the Related Art
Recently, endoscopes have come into wide use in the field of medicine. The endoscopes have an elongated insertion portion which is inserted into a subject. A bending portion configured to be bendable is installed on a distal side of the insertion portion.
The bending portion of the endoscope is operated by pulling and relaxing a wire from a rear side of the insertion portion, but there are also motor-operated endoscopes which operates the bending portion using driving force of a motor serving as bending drive means to improve operability of the bending portion.
However, when conducting endoscopy in a crooked body cavity such as an intestinal tract, it is difficult for an inexperienced surgeon to move a distal end of the endoscope to a target position and pass through a target line (e.g., a center line of the intestinal tract).
To deal with this, there is an endoscope system which determines, based on endoscopic images, in what direction the distal end of the endoscope should be directed (e.g., toward a dark part), determines a target position for the distal end of the endoscope based on the direction thus determined, and performs bending operations to bring current position of the endoscope's distal end into coincidence with the target position for the distal end of the endoscope.
On the other hand, Japanese Patent Application Laid-Open Publication No. 2006-192056 discloses an endoscope control unit which includes a bending operation storage means which stores bending operations of a bending portion; and parameter storage means which prestores operation parameters corresponding to the bending operations of the bending portion, wherein the endoscope control unit controls an amount of bending of the bending portion by retrieving an operation parameter corresponding to a bending operation of the bending portion from the parameter storage means.
The parameter storage means stores data on a total number n of bend commands, counted from immediately after production of the endoscope system, given by a bend command input means with respect to which direction to operate the bending portion, up, down, left, or right.
The conventional example discloses a technique for performing bending operations using settings information which, being prestored in memory, represents pulse widths (of a drive signal) corresponding to different numbers of bends.